Various manufacturing processes require that substrates be linearly conveyed along a plurality of conveyors. An example of such a process is the production of thin film photovoltaic (PV) modules (“panels”), wherein individual glass substrates are linearly conveyed through a vacuum deposition chamber. Conventional vacuum deposition chambers are divided into multiple sections, such as a heating section (wherein the glass substrates are heated to a desired temperature), a vapor deposition section (wherein a thin film layer of a photo-reactive material is deposited onto the surface of the pre-heated glass substrates) and a cooling section (wherein the glass substrates are cooled). Typically, each section includes one or more individually controlled conveyors for conveying the substrates through the section. In addition, one or more conveyors may also be disposed upstream and downstream of the vacuum deposition chamber for moving the substrates through one or more vacuum lock stations.
Typically, substrates moving through a vacuum deposition chamber must be conveyed at a constant speed through the vapor deposition section to ensure that a uniform layer of material has been deposited onto the substrates. However, due to the vacuum locks positioned upstream of the vacuum chamber, conveying a new substrate into the vacuum deposition chamber involves a series of start/stop moves. This series start/stop moves creates a large gap between the new substrate and downstream substrates within the vacuum disposition chamber. Such a large gap reduces ration of the amount of material deposited onto the substrates to the amount of material deposited onto the conveyor (i.e., between the substrates), which decreases the overall efficiency of the process.
Accordingly, a system and method for gapping conveyed substrates that allows the gap between adjacent substrates to be minimized would be welcomed in the technology.